Rotary oil burners



Dec. 10, 1957 J. J. MOGILLIS ETAL I 2,815,306

ROTARY on. BURNERS Filed June 1, 1954 2 Sheets-Sheet 1 J. J. McGiLus ET AL 2,815,806

Dec. 10,1957

' ROTARY on. BURNERS 2 Sheets-Sheet 2 Filed June 1, 1954 [tier/26y Patented Dec. 16, W?

ROTARY 01L BURNERS John J. McGillis and Hugh D. McGillis, Brockton, Mass.

Application June 1, 1954, Serial No. 433,486

6 Claims. (Cl. 158-77) This invention relates to improvements in rotary type oil burners. It relates more particularly to improvements in the rotary head and associated means for controlling and conditioning air for combustion which is mixed with the oil only after the oil has been atomized and discharged from the rotating head. Such a rotary type oil burner is disclosed in our co-pending application Ser. No. 274,342, filed March 1, 1952, now Patent No. 2,738,837, and the present invention is directed to air-controlling and air-conditioning features which substantially increase the efficiency and capabilities of rotary oil burners as compared with the oil burner of our said co-pending application and all other comparable oil burners of which we are aware.

Oil burners of the general type to which the invention relates customarily have a rotary head comprising a pair of opposed dished plates or disks fixed in spaced relation on the upper end of a vertically disposed hollow shaft through which oil delivers between the plates or disks. Air also delivers between the plates or disks in the prior comparable oil burners, excepting the oil burner of our said co-pending application, and this air mixes with the oil in the atomizing process, and an atomized mixture of oil and air discharges around the periphery of the rotating head to which other air is added at the region of combustion of the mixture. In our said copending application, there is disclosed an oil burner whose rotating head discharges undiluted atomized oil to the region of combustion at which the air for combustion and for further break-up of the oil particles is added. Our present invention utilizes this same principle of discharge of undiluted atomized oil from the rotating head but provides novel features whereby available air is more effectively utilized and controlled to attain greater combustion efliciency, especially when burning the heavier grades of oil, such as No. 6 oil, for example.

Hence, it is among the objects of our present invention to provide a rotary type oil burner wherein a rotating head discharges an annular stream of substantially undiluted atomized oil to the region of combustion and wherein two annular forced streams of air intersect each other and the stream of substantially undiluted atomized oil at the region of combustion, both of said streams of air being drawn in substantial part from the combustion chamber Within which the oil burner is operating. Ac cording to the invention, a controllable volume of relatively cold air is drawn to the oil burner from an outside source and is augmented by a substantial volume of heated air drawn from the combustion chamber within which the oil burner is operating, and this mixture of relatively cool and of heated air is propelled in cooling relation to the rotating head Without entering between the plates or disks of the head and is directed thence in the two said annular intersecting forced streams at the combustion region.

Another object of the invention is to provide a rotary type oil burner'whose rotating head discharges substantially undiluted oil in an annular stream of atomized oil to a combustion region within a combustion chamher, and wherein the rotating head has means associated with it for drawing heated air in substantial volume from said combustion chamber and propelling it in two forced annular streams which intersect each other and said annular stream of atomized oil at the combustion region.

A further object of our present invention is to provide an oil burner wherein a rotating atomizing head discharges substantially undiluted atomized oil in an annular stream, and wherein air for combustion is drawn in substantial volume from the supply of heated air in the combustion chamber and is propelled in two annular intersecting streams which intersect each other and the annular stream of atomized oil substantially at the region of combustion within the combustion chamber.

It is, moreover, our purpose and object generally to improve the structure and operative etliciency of oil burners and especially rotary type oil burners whose rotating heads discharge annular streams of substantially undiluted atomized oil to a combustion region within a combustion chamber.

In the accompanying drawings:

Fig. l is a cross-sectional view, with some parts in elevation, of the upper portion of a rotary oil burner embodying features of our invention;

Fig. 2 is a bottom plan view of the rotary head of the oil burner of Fig. 1, with portions in cross-section on line 2--2 of Fig. l; and

Fig. 3 is a top plan view, with portions in cross-section, on line 3-3 of Fig. 1.

Referring to the drawings, a rotary oil burner head, indicated generally at 10, may be supported in a conventional manner by legs or posts 12 which also may support an electric motor 1.4 with means (not shown) for adjustment of the motor vertically in general parallelism with the legs. Usually, the legs 12 also include provision for adjustment of their lengths to facilitate proper positioning of the head 12 with its axis vertical even though a floor or other support may be uneven.

A generally horizontally disposed platform 16 is fixed on the upper ends of legs 12 and has a relatively large central opening 18 within which an annular sleeve 29 is vertically adjustable by means of an adjusting screw 22. The screw 22 is rotatably fixed on platform 16 with its threaded shank extending through and engaging threads in a projecting ear 24 on sleeve 20. An upstanding flange portion 26 on platform 16 closely surrounds sleeve 20 for guiding the latters movements and for restraining the sleeve against vibration in all of its positions of vertical adjustment. Flange portion 26 has an annular enlargement 28 which is hollow at 30 for accommodating the screw 22 and car 24.

Refractory elements 32 of a heater ordinarily rest on platform 16 outward of and all around the annular enlargement 28 of flange portion 26.

Motor 14 has a vertically disposed shaft 34 of conventional hollow form, and oil from any suitable source is conducted upwardly through the shaft to the burner head it) which is fixed on an extension of motor shaft 34 for rotation with the shaft when motor 14 is running.

As represented in Fig. l, the hollow motor shaft 3 has its upper end connected at 36 to a hollow extension shaft 38 on the upper end of which are rigidly mounted elements of rotary burner head 10. Extension shaft 38 has the cylindrical enlargement 40 thereon, and has one threaded portion 42 below the head it) and another threaded portion 44 which is of reduced diameter at the upper end of extension shaft 38. Two dished annular plates 46 and 48 are clamped rigidly to the extension shaft 38 with their dished sides toward each other and with their peripheral lips spaced slightly apart. The upper plate 46 has a central hole for receiving the upper a threaded end portion 44 of extension shaft 38 and is clamped against the shoulder at the upper side of enlargement 40 by means of nut 50, with a third dished plate 52 and spacing collar 54 intervening between the plate 46 and nut 50. The lower dished plate 48 has a central opening whereby it may be arranged on extension shaft 38 before the latters lower end is connected at 36 to the'm-otor shaft 34, and this plate may be slid along extension shaft 38 into engagement with the shoulder at the lower side of enlargement 40. Plate 48 has a depending annular flange 48a Whose lower edge is adapted to be engaged by a nut 56 screwed on threaded portion 42 of extension shaft 38. When the nuts 50, 56 are tightened, the three dished plates 46, 48, 52 become fixed to'the extension shaft 38 for rotation therewith.

However, before the dished plates are clamped to extension shaft 38, a series of short rigid tubes 58 are loosely assembled in spaced positions to extend generally in verticaldirections across the space between the dished plates 46, 48. Conveniently, the opposite ends of tubes 58 are exteriorly tapered for entering plate holes 60 which may be slightly smaller in diameter than the exterior diameter of the tubes. Hence, when the plates 46, 48 are clamped to extension shaft 38 by tightening nuts 50, 56, the tapered ends of the tubes 58 become gripped by the walls of the plate holes 60 and the tubes plug the holes against any appreciable passage of air between the exterior surfaces of the tubes and the walls of the plate holes 60. However, the tubes 58 provide air passages for flow of air from the under side of burner head to the space'between plates 46 and 52, with none of this air having access to the space between plates 46 and 48.

The hollow or bore of extension shaft 38 extends into and terminates within the enlargement 40, as at 41, and a series of relatively small diameter passages 62 extend radially outward through the enlargement 40 from the terminal portion 41 of the bore. Hence, oil conducted upward through motor shaft 34 and shaft extension 38 delivers through the radial passages 62 into the space between dished plates 46, 48. Preferably, the hollow motor shaft 34 and/or the hollow extension shaft 38, or any desired portions of the lengths thereof, will be provided with means, such as the interior threads 39 in shaft extension 38, for inducing or aiding the upward travel of oil and especially the heavier and more viscous oils, such as No. 6 fuel oil, for example. A generally similar result may be attained with one or more closely coiled springs (not shown) which may be inserted within the hollow of either or both of the shafts 34, 38. Use of a coiled spring has the advantage that it is readily removable for periodic cleaning.

Oil delivering into the space between the relatively high speed rotating dished plates 46, 48 is carried outward on and between the plates by centrifugal force with substantial atomization and/or vaporization of the oil being accomplished between the plates 46, 48 while air is excluded from entering between the plates. Hence, atomized and vaporized oil substantially undiluted by air discharges from the slightly spaced peripheral lips of the plates approximately in a horizontal plane with a further atomizing efiect resulting from the centrifugal discharge of the oil into space annularly all around the rotating head. The horizontally discharged oil is subjected to the final atomizing effect of two relatively high velocity annular streams of air which intersect each other and the delivering oil relatively close to the peripheral lips of plates 46, 48 all around the burner head 10.

A fan may be provided on extension shaft 38, if desired, and as shown in our said co-pending application Serial No. 274,342, for drawing air into the adjustable sleeve and for propelling air on courses to provide the said intersecting streams of air annularly around the rotating burner head 10. We prefer, however, to provide fan blades 47 and 49 on the dished plates 46 and 48 respectively, and at peripheral regions of these plates. The fan blades 47 are shown secured at 47' to the dished plate 46 and they are located in the space between the similarly inclined outer portions of the dished plates 46 and 52, with the formation :of the blades such that they propel air outwardly and downwardly across the horizontal plane of delivery of oil from the rotating head 10. The fan blades 49 are secured at 49 to dished plate 48 and they are located in the space between the inclined outer portion of dished plate; 48 and the upper end of an auxiliary sleeve 20' which is of smaller diameter than sleeve 20 and which is rigid on sleeve 20 with the walls of the two said sleeves spaced from each other. The formation of blades 49 is such that they propel air outwardly and upwardly across the horizontal plane of delivery of oil from the rotating head 10 at an annular region of intersection of the two streams of air propelled by the fan blades 47, 49.

It will be obvious from the foregoing description, that rotation of burner head 10 will result in air being drawn into the lower end of adjustable sleeve 20, and this incoming relatively cold air is directed inward by the annular baffle means 64 at the lower end portion of sleeve 20. Hence, all of the incoming cold air enters the auxiliary sleeve 20' and substantial amounts thereof are drawn through the tubes 58 into the space between dished plates 46, 52 whence it is propelled by fan blades 47 outwardly and downwardly to provide one of the mentioned annular intersecting streams of air. Other substantial .amounts of the relatively cold air drawn into auxiliary sleeve 20' is propelled outwardly and upwardly by fan blades 49 to provide the other of the mentioned annular intersecting streams of air.

According to the invention, however, relatively hot air from the combustion chamber is drawn into the auxiliary sleeve 20 and mixes with the cold air therein. This hot air'enters between the two sleeves 20, 20' at the upper end portions thereof and passes downward between the sleeves and then upward through the lower end of auxiliary sleeve 20, with the previously described annular batfiemeans 64 serving to direct the hot air upwardly into sleeve 20'. Actually, an annular blanket of flame tends'to enter between the sleeves, and the air which ultimately passes downward between the sleeves and upward into' auxiliary sleeve 20' is extremely hot air. As a result, the annular intersecting streams of air which effect final atomizing of the oil delivering from head 10 are streams of relatively hot air which supply the oxygen for ready and efficient combustion of the delivering oil.

The amount of cold air drawn into the sleeves 20, 21' may be regulated to suit particular requirements and conditions by a manually operable shutter-type valve means indicated generally at 66 which may have an actuating handle 68 thereon by which the shutter elements 67 may be operated to reduce or increase the size of the air inlet passage through the valve means. Also, the size of the annular air passage between dished plate 48 and the top edge of auxiliary sleeve 20' may be varied by means of the adjusting screw 22. Hence, the volumes of air in the intersecting annular streams may be regulated to attain an eflicient oil and air mixture for combustion. Also, the volume of air in the annular intersecting stream which is propelled by the fan blades 49 may be regulated with respect to the other intersecting stream. Perhaps more important, however, is the provision of high temperature air for admixture with the entering cold air and the provision for regulating the relative proportions of hot and cold air in the annular intersecting streams by means of the manually operable shutter-valve means 66.

Our improved rotary oil burners as herein disclosed are demonstrating an operative efiiciency substantially greater than any prior comparable oil burner of which we are aware. We provide against any appreciabledilution of oil by air within our oil burner head 10. Hence, atomized'and/or vaporized oil discharging horizontally from the rotating head is substantially free of air which avoids any possibility of flash backs or burning of oil within the head which is a common fault of rotary type oil burners under heavy duty and when the burners are required to operate for prolonged periods. All of the air propelled through and around our disclosed burner head serves to cool the head and the parts thereof with none of this air getting into the atomizing chamber or space between dished plates 46, 48. Our combustion results, and the nature of the flame produced with our disclosed rotary burner, are operatively superior to what have been attainable with prior comparable burners, in that the flame has a rolling and bubbling character and notable absence of smoke, indicating high combustion efficiency, with CO readings as high as 15%.

It will be obvious that various changes may be made in the details of our disclosed rotary oil burner without departing from the spirit and scope of the invention as defined in the appended claims, and it is intended that the patent shall cover, by suitable expression in the appended claims, whatever features of patentable novelty exist in the invention disclosed.

We claim as our invention:

1. In a rotary oil burner having a circular rotating head rotating about a vertical axis for centrifugal generally horizontal discharge of atomized oil annularly around the head into a combustion chamber, and having means for directing annular streams of air in directions to intersect each other and the discharging oil annularly around and relatively close to the periphery of the head, the combination therewith of an outer cylindrical sleeve below said head and concentric about the vertical axis of the head, an inner cylindrical sleeve fixed within the outer sleeve and concentric therewith, said inner sleeve having substantially smaller diameter than the outer sleeve to provide an annular air passage between them, and the upper end of said inner sleeve being arranged and adapted to coact with said burner head to provide an annular passage extending upwardly and outwardly between the head and the upper end of said inner sleeve for passage of one of said annular intersecting streams of air, said means for directing annular streams of air acting to draw relatively cold air in substantial volume into the lower end of said inner sleeve and upward within the inner sleeve to provide an upwardly moving body of cold air having area approximating the area of the passage through the inner sleeve, said means acting also to simultaneously draw hot air from the combustion chamber into the upper end of said outer sleeve and downwardly between the two sleeves and thence annularly into peripheral portions of said upwardly moving body of cold air annularly around said body, whereby said hot air moves upwardly within said inner sleeve in surrounding relation to a substantial central mass of the upwardly moving cold air thereby to provide a major portion of the air for said one of the annular intersecting streams of air issuing from said annular passage between said head and the upper end of the inner sleeve, said central mass of cold air serving to cool said head and providing the air for the other of said annular intersecting streams of air, and means for adjusting said outer sleeve axially to move said upper end of the inner sleeve toward and from said burner head thereby to vary the size of said annular passage between the head and the upper end of said inner sleeve.

2. In a rotary oil burner, the combination as defined in claim 1 wherein manually operable valve means adjacent to the lower end of said inner sleeve is adjustable to vary the relative proportions of cold and hot air passing upwardly within said inner sleeve.

3. In a rotary oil burner, the combination as defined in claim 1 wherein said burner head has upper and lower walls defining an atomizing chamber within the head, and wherein conduit means define air passages extending across said atomizing chamber for conducting air in said central mass of cold air from the under side to the upper side of said head for cooling the head while maintaining said conducted air from entering said atomizing chamber, said conducted air which reaches the upper side of said head being directed outwardly and downwardly to provide the said other of said annular intersecting streams of air.

4. In a rotary oil burner having a circular rotating head rotating about a vertical axis for centrifugal generally horizontal discharge of atomized oil annularly around the head into a combustion chamber, and having air propulsion means for directing two annular streams of air in directions to intersect each other and the discharging oil annularly around and relatively close to the periphery of said head, the combination therewith of means for controlling the volume and character of said annular intersecting streams of air comprising two concentric sleeves below and axially aligned with said head to provide a main air flow passage upward through said inner sleeve and an auxiliary air flow passage downward between said sleeves, said inner sleeve having its upper end spaced from said burner head to provide an annular passage therebetween through which one of said annular intersecting streams of air is directed outwardly and upwardly, means for conducting air through said burner head from the under side to the upper side thereof and thence outwardly and downwardly to provide the other of said annular intersecting streams of air, means for manually adjusting the upper end of said inner sleeve toward and from said burner head thereby to vary the size of said annular passage between it and the head, the lower end of said inner sleeve being open for passage of cold air into and upwardly through the inner sleeve, and the upper end of said outer sleeve being open for entrance of hot air from the combustion chamber into the outer sleeve and for passage of this hot air downwardly between the sleeves and annularly into said upwardly moving cold air in surrounding relation to substantial volumes of said cold air, whereby said surrounded cold air moves upwardly to said head and through said means for conducting air through the head, and said surrounding hot air moves upwardly to and through said annular passage to provide predominantly hot air in said one of the annular intersecting streams of air, and manually operable valve means adjacent to the lower end of said inner sleeve for regulating the proportion of: cold air in the said mixture passing upward within the inner sleeve.

5, In a rotary oil burner, a circular rotating head rotative about a vertical axis for centrifugal generally horizontal discharge of atomized oil annularly around the head into a combustion chamber, propulsion means on upper and lower peripheral portions of the head for propelling air in two annular streams which intersect each other and the discharging oil relatively close to the periphery of said head and annularly around the head, a relatively large-diameter sleeve below and concentric with the head providing an air passage through which air is drawn by said propulsion means, to supply the air for said annular intersecting streams of air, there being passages leading through said head from the under to the upper side thereof, and an annular passa e between said head and the upper end of said sleeve through which air from within said sleeve is directed outwardly and upwardly to provide one of said annular intersecting streams of air, a second sleeve surrounding the first mentioned sleeve and spaced therefrom to provide an annular air passage between them, the upper end of the latter said passage being open for entrance'of hot air from the combustion chamber and the lower end thereof being open for delivery of said hot air into the lower end of the first mentioned sleeve annularly adjacent to the walls of the latter said sleeve, said lower end of the first mentioned sleeve being open for passage of cold air into and upwardly through said first mentioned sleeve, whereby said delivered hot air surrounds cold air within said first mentioned sleeve and passes upwardly in said surrounding relation to the cold air to provide predominantly hot air I" K in one of said annular intersecting streams of air, said surrounded cold air passing upwardly to and through said head for cooling the head and supplying the air for the other of said annular intersecting streams of air, and means for manually controlling the proportions of cold and hot air in said mixture.

6. In a rotary oil burner, a shaft mounted for rotation in a generally vertical position, a burner head fixed concentrically on the upper end portion of said shaft and having spaced upper and lower walls defining an atomizing chamber therein, means at the peripheral region of said head defining an annular opening for centrifugal discharge of atomized oil from said chamber, power means for rotating said shaft and head, relatively fixed means below the burner head and having a relatively large opening therein through which said shaft extends, an outer cylindrical sleeve adjustably mounted in said relatively large opening, an inner cylindrical sleeve mounted on said outer sleeve with its walls spaced from the outer sleeve to provide an annular air passage therebetween, said inner sleeve having its upper end arranged and adapted to coact with said burner head to provide an annular air passage leading from within the inner sleeve and extending upwardly and outwardly between the burner head and the upper end of the inner sleeve, means rotatable with said shaft and head for inducing flow of cold air into the lower end of said inner sleeve and upwardly through the inner sleeve and for inducing flow of hot air downwardly through said annular passage between said sleeves and thence upwardly within said inner sleeve in surrounding relation to upwardly moving cold air within said inner sleeve, whereby said surrounded cold air flows upwardly into cooling relation to said head and said surrounding hot air flows upwardly into and through said annular passage for providing an upwardly and outwardly directed annular stream of predominantly hot air adjacent to said discharge opening in said head, and means for adjusting said outer sleeve to move the upper end of said inner sleeve toward and from the burner head thereby to vary the size of said annular air passage between the head and the upper end of the inner sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 2,050,577 Littleton Aug. 11, 1936 2,200,278 Johnston May 14, 1940 FOREIGN PATENTS 104,246 Great Britain Mar. 1, 1917 

